Bolt threading machine



Dec. 8, 1964 R. L. KENDRICK BOLT THREADING MACHINE Filed Jan. 12. 1961 V. e #0 #5 M United States Patent 3,160,034 BGLT 'HREEADMG MACHINE Ralph L. Kendrick, Rockford, ill, assignor to imperial Wire iroducts, Inn, Rockford, ill., a corporation of Maryland K lled Jan. 12, 1961, Ser. No. 82,318 7 Claims. (til. 8ti-3) This invention relates to a bolt threading machine and is more particularly concerned with the conversion of a horizontal hand-feed thread rolling machine of the Waterbury-Farrel type to automatic feed to the end that various kinds of headless double threaded bolts, such as hanger bolts, used in large numbers in the furniture industry, where one end has a wood screw thread for driving into the wooden part and the other end has a machine screw thread for application of a fastener nut, may be produced in large quantities at much lower cost.

More specifically stated, the invention contemplates the addition to the otherwise hand-fed thread rolling machine or" feed rollers which in each operation are turned through a predetermined angularity to feed a predetermined length of wire through a cut-off die, the length being variable by means of a simple screw threaded adjustment crank pin that is pivotally connected to one end of a pitman rod that oscillates an arm through a given angularity in each operation of the machine to transmit through a clutch a predetermined fraction of a turn to one of the feed rollers, the other being operated through gears through a corresponding angularity. This is a departure from earlier machines designed for a similar purpose, where the wire was usually fed in under friction against an adjustable stop to predetermine the ultimate length of the blank, but that design had many objections and was far more complicated and expensive and not nearly as versatile and adaptable as the present design. Once the wire is extended vertically downwardly to the desired length from the die, in accordance with my invention, a cut-ofi knife moving horizontally with the reciprocable carriage cuts the wire and the blank drops by gravity against a vertically adjustable stop on the bed of the machine movable in a vertical plane between the fixed threading die on the bed and the movable die on the carriage, the vertical adjustment of the stop predetermining what length of one end portion will be given the wood screw thread between cooperating thread rolling die portions on the two dies and what length will be given the machine screw thread between the other thread rolling die portions on said dies. A horizontally slidable finger, which is reciprocable in timed relationship to the carriage but through only a small fraction of that extent of movement, pushes the blank forward between the dies to start the thread rolling operation, and at the end of the forward travel of the carriage, the cutoff knife cuts off tie next blank, the feed rolls having in the meantime fed in the required length of wire through the cut-off die. The finger referred to is retracted immediately after pushing the blank forward between the dies and is, therefore, out of the way when the next blank drops;

The invention is illustrated in the accompanying drawing, in which:

FIG. 1 is a front View of a horizontal thread rolling machine of the kind mentioned, embodying my invention;

FIG. 2 is a plan view on the line 22. of FIG. 1 with intermediate portions of the bed and carriage broken away to enable the showing of front and back portions on a larger scale than would otherwise be possible;

FIG. 3 is a fragmentary rear view;

FIG. 4 is an enlarged sectional detail of a portion of,

FIG. 2 taken on the line 44 of FIG. 1; and

FIGS. 5 and 6 are side views of a blank and a hanger bolt produced from such a blank, respectively.

ice

The same reference numerals are applied to corresponding parts throughout the views.

Referring to the drawing, the reference numeral 7 in FIG. 5 shows a wire blank full size, and the reference numeral 8 in FIG. 6 shows the hanger bolt full size produced in the horizontal roll threading machine indicated generally by the reference numeral 9 in FIGS. 1 and 2, which those skilled in theart will recognize as a modified Waterbury-Farrel machine. While I have disclosed a hanger bolt, which I stated before are used in large numbers in the furniture industry, having one end portion 10 with a wood screw thread to drive into the wooden part as, for example, on a Leg, and having a machine screw thread 11 on the other end portion designed for application of a fastener nut, the machine, it will be understood, is adapted for the double threadingof various kinds of headless bolts with machine screw threads on both ends,

or wood screw threads on both ends or, for that matter, either form of thread on only one end portion as, for example, where the blank, after the threading operation, is to be formed into an eye or hook or some other form. For the double threading of hanger bolts, the roll threading machine 9 has the stationary die 12 on the bed 13 provided on its upper half 14 with longitudinally extending threads for the rolling of the machine screw thread 11, and on its lower half, longitudinally extending threads 15 for the rolling of the Wood screw threads 10, and the movable die 16 on the reciprocable carriage 17 has related longitudinally extending threads 14' and 15' on the upper and lower halves thereof, respectively. In each reciprocation of the movable die 16 relative to the stationary die 12, a blank 7 is threaded at both ends and dropped into a receptacle 1%, as indicated at the left-hand end of FIG; 1 by the two arrows 19 and 20. In a hand-feed Waterbury- Farrel machine, the blanks 7 would, of course, be cut to length in a separate operation and dropped one at a time into the loading station 21 in timed relationship to the horizontal reciprocation of a slide or finger 22 operated in a guide 22' in timed relationship to the reciprocation of the carriage 17 by means of a rocker arm 23, the latter being one of a pair of arms with rocker arm 24 operable by means of a link 25 from an arm 26 that is in turn operated intermittently by a rotary cam 27 turning with the flywheel on the main drive shaft 28 of the machine from which the carriage 17 receives its reciprocatory movement in the usual way by means of a pitman rod, the pitman rod being adjustably connected with the flywheel by means of a radially adjustable crank pin so that fine adjustment may be made of the travel of the carriage 17 to suit the requirements of any given job. Obviously, with hand feed, the production is limited and the cost per piece runs rather high, especially since the blanks have to be cut to length in a separate operation on another machine, thereby further reducing the shops output per day.

In accordance with my invention, the wire W from which the blanks 7 are to be cut is supplied from a reel (not shown) and is fed vertically downwardly through a cut-off die 29 disposed directly over the loading station 21 with a vertical guide tube 3% and after a predetermined length of wire suihcient for a blank 7 has been fed downwardly by clockwise rotation of a feed roller 31 and simultaneous counter-clockwise rotation of a companion feed roller 32, both through the same predetermined angularity, a cut-off knife 33 mounted for horizontal reciprocation with the carriage 17 cuts off the length of wire 34 extending downwardly from the cut-off die 29 to provide the next blank 7 at the conclusion of each thread rolling operation, the blank 7 immediately after being cut dropping by gravity into place in a vertical plane between the dies 12 and 16 in the loading station 21 preparatory to the next roll threading operation. The finger 22, which is moved forwardly to push the blank 7 forwardly between the dies 12 and 16 as the carriage 17 moves forward, is retracted immediately thereafter and is, therefore, out of the way by the time the carriage 17 approaches the end of its forward travel, when the cut-01f knife 3.3 cuts off the extending end portion 34 of the wire to provide the next blank, and, hence, there is nothing to interfere with the blank dropping vertically into the loading station 21 against the vertically adjustable horizontal stop 35. There is a vertical shoulder 36 in the loading station 21 to the right of the blank 7 against which the blank-comes to rest for an instant the moment it strikes the stop 35 and just before the finger 22, moving forwardly past the shoulder 36, pushes the blank on its way between the dies.

12 and 16 at the commencement of the roll threading operation. Vertically adjustable screw 37 is adapted to be manually adjusted to raise or lower the stop 35 and the blank 7 in relation to the dies 12 and 16, and in that way it is obvious that one may shorten or lengthen the wood screw threads 1! and proportionately increase or decrease the length of the machine screw threads 11. The overall length of the double threaded bolt may be varied by radial adjustment of the crank pin 38 relative to the auxiliary flywheel 39 that turns with the main flywheel previously mentioned and is provided on the opposite end of the main drive shaft 28, the radial adjustment being similarly obtained by rotary adjustment of a diametrically extending screw 49, the radius of operation of the crank pin 38 determining the angularity of oscillation of a rocker arm 41 operated from the crank pin 38 by means of a pitman rod 42 and transmitting only clockwise rotation to a gear 43 through a one way clutch 44 whereby to transmit a predetermined rotation to feed roller 32 and simultaneously to the other feed roller 31 through another gear 45 meshing with gear 43.

In operation, it should be clear from the foregoing description that the desired close accuracy as to regulation of length of wire blank for an article of the hanger bolt variety is obtainable using friction feed rollers 31 and 32 operated in the manner described and having their feed movement adjusted in the manner described. Hence, by eliminating what was heretofore considered essential, namely, the feeding of the Wire up against a positive step that was adapted to be adjusted for predetermining the length of the blanks, I have been able to simplify the machine considerably, not only from the standpoint of the elimination of all of the complications that were inevitable with the use of a positive stop, but also from the standpoint that with the present unique feed method the blanks can drop directly by gravity into the loading station instead of having to be transferred laterally from a cut-off station to a feed-in station. It is also a much simpler matter with the present design to vary the length of the blank, as that involves only a simple adjustment of the crank pin 38, and whatever vertical adjustment may be necessary for the stop 35, namely, adownward adjustment for a longer blank and an upward adjustment for a shorter one.

In closing, attention is called to the spring-pressed plunger 46 which is disposed slightly below the lower end of the cut-off die 29 and above the upper end of the vertical guide tube 30 and slidable in a horizontal hole in the vertical arm 47 of the L-shaped bracket 48 that supports the guide tube 39. This plunger 45 is adapted to be pushed back against the action of a coiled compression spring 49 when the cut-off knife 33, in cutting off the protruding end portion 34- of the wire W, presses the upper end of this length of wire against the enlarged end of the plunger 46, whereupon the plunger 46 returns with the knife 33 as the latter backs away, and, hence, for an instant, the upper end portion of the cut-off length of wire 34 is gripped between the plunger 46 and the cut-off knife 33 in dead center relationship to the loading station 21, so that in each cutting operation, the blank drops in precisely the same accurate way into the loading station. A nut 50 on the threaded outer end 51 of the plunger as is eecurately adjusted to predetermine the extent of projection of the plunger 46, and a lock-nut 52 is tightened to maintain this adjusting nut 50 in its adjusted condition.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my inven tion. The appended claims have been drawn to cover all legitimate modifications and adaptations.

I claim: 7

1. A headless blank cutter and feeder for a thread rolling machine comprising a first stationary fiat vertical threading die having an infeed end, a second relatively reciprocable flat vertical threading die in spaced parallel relationship thereto, and a finger reciprocable relative to and between said dies at the infeed end of said first die in a predetermined timed relationship to the reciprocation of said second die, said blank cutter and feeder comprising a cut-off die and a guide tube together adapted to receive a length of wire of the diameter of the blanks to be threaded on a vertical line which when extended downwardly ends behind the infeed end of the first die and in front of said finger, means for intermittently feeding such round wire vertically downwardly through said cutoff die once per reciprocation of said second die to provide a predetermined length of wire for a blank below the cut-off die and guided in the guide tube, a cut-off knife reciprocable horizontally relative to the guide tube past and in shearing relationship to the lower end of said cutoif die, a stop for abutment by the lower end of the blank disposed on the aforesaid vertical line below the level of the finger, means for retaining each blank after it is cut but releasing it to drop by gravity against the stop in timed relation to the rearward movement of the cut-off knife, means for operating said wire feeding means in timed relation to said second die, and means for operating said knife in timed relation to said wire feeding means, finger, and second die, whereby a single blank of the predetermined length is dropped by gravity on the aforesaid vertical line in proper timed relationship to forward movement of the finger and second die in each cycle of operation of the machine.

2. A blank cutter and feeder as set forth in claim 1 wherein the means for retaining each blank after it is cut but releasing it to drop by gravity in timed relation to the rearward movement of the cut-oft knife comprises a spring pressed plunger guided for reciprocation horizontally relative to said cut-off die and below the same, said plunger being disposed on a horizontal line with the knife so as to be pushed back against spring action with the Wire in the cutting off thereof by the knife, whereby the severed wire blank is gripped momentarily between the knife and plunger after the cutoif operation as the knife returns and the plunger returns with it up to the aforesaid vertical line, the blank being then released to drop by gravity along said vertical line.

3. A blank cutter and feeder as set forth in claim 1, wherein the first die has two vertically spaced sets of roll threading threads provided thereon, and said second die has two similarly vertically spaced sets of roll threading threads provided thereon in cooperating alignment with the threads on the first die, the machine including means for adjusting the stop vertically relative to said dies.

4. A headless blank cutter and feeder for a thread rolling machine comprising a bed, a carriage reoirpocable thereon, a first stationary thread rolling die on the bed having an infeed end, and a second reciprocable thread rolling die on the carriage, said blank cutter and feeder comprising a vertical guide tube on a vertical line over the infeed end of the first die, a wire cut-oft die in vertically aligned relation to and above said tube, two oppositely rotatable wire feed rolls in a vertical plane through said vertical line between which round wire for cylindrical blanks to be threaded is frictionally feedable on said line, a horizontal cut-off knife reciprocable with the carriage relative to the bottom of the cut-off die, a stop for abutment by the lower end of the blank disposed on the afore-.

said vertical line to locate said blank properly with respect to the thread rolling dies, means for retaining each blank after it is cut but releasing it to drop by gravity against the stop in timed relation to the rearward movement of the cut-off knife, and means for turning said rolls through a predetermined angularity in opposite directions in timed relation to the carriage reciprocation, the machine including afinger reciprocable between the first and second dies in timed relation to the carriage reciprocation whereby to push a blank forward between the dies immediately after it is cut off and dropped by gravity on said vertical line into engagement with the stop in front of the finger.

5. A blank cutter and feeder as set forth in claim 4 1 wherein the means for turning said rolls is adjustable to vary accordingly the included angularity of turn upon each operation and accordingly vary the length of wire blank cut in each operation of the knife.

6. A blank cutter and feeder as set forth in claim 4 wherein the first die includes two sets of thread rolling threads extending horizontally thereof in vertically spaced relation and the second die likewise, the stop being vertically adjustable relative to the infeed end of said first die.

7. A blank cutter and feeder as set forth in claim 4 wherein the means for retaining each blank after it is cut but releasing it to drop by gravity against the stop in timed relation to the rearward movement of the cut-01f knife comprises a spring pressed plunger guided for reciprocation horizontally relative to said cut-01f die and below the same, said plunger being disposed on a horizon-' tal line with the knife'so as to be pushed back against spring action with the wire in the cutting off thereof by the knife, whereby the severed wire blank is gripped momentarily between the knife and the plunger after the cut-0E operation as the knife returns and the plunger returns with it up to the aforesaid vertical line, theblank being then released to drop by gravity along said vertical line.

References Cited in the file of this patent UNITED STATES PATENTS 1,841,800 Gale Jan. 19, 1932 2,094,850 Schoenrock Oct. 15, 1937 2,364,442 I Hoern Dec. 5, 1944 2,594,708 Amiet Apr. 29, 1952 2,655,212 Stewart Oct. 13, 1953 2,859,647 Nielsen Nov. 11, 1958 2,985,352 Kuhlrnann May 23, 1961 FOREIGN PATENTS 619,428 Great Britain Mar. 9, 1949 OTHER REFERENCES 

1. A HEADLESS BLANK CUTTER AND FEEDER FOR A THREAD ROLLING MACHINE COMPRISING A FIRST STATIONARY FLAT VERTICAL THREADING DIE HAVING AN INFEED END, A SECOND RELATIVELY RECIPROCABLE FLAT VERTICAL THREADING DIE IN SPACED PARALLEL RELATIONSHIP THERETO, AND A FINGER RECIPROCABLE RELATIVE TO AND BETWEEN SAID DIES AT THE INFEED END OF SAID FIRST DIE IN A PREDETERMINED TIMED RELATIONSHIP TO THE RECIPROCATION OF SAID SECOND DIE, SAID BLANK CUTTER AND FEEDER COMPRISING A CUT-OFF DIE AND A GUIDE TUBE TOGETHER ADAPTED TO RECEIVE A LENGTH OF WIRE OF THE DIAMETER OF THE BLANKS TO BE THREADED ON A VERTICAL LINE WHICH WHEN EXTENDED DOWNWARDLY ENDS BEHIND THE INFEED END OF THE FIRST DIE AND IN FRONT OF SAID FINGER, MEANS FOR INTERMITTENTLY FEEDING SUCH ROUND WIRE VERTICALLY DOWNWARDLY THROUGH SAID CUTOFF DIE ONCE PER RECIPROCATION OF SAID SECOND DIE TO PROVIDE A PREDETERMINED LENGTH OF WIRE FOR A BLANK BELOW THE CUT-OFF DIE AND GUIDED IN THE GUIDE TUBE, A CUT-OFF KNIFE RECIPROCABLE HORIZONTALLY RELATIVE TO THE GUIDE TUBE PAST AND IN SHEARING RELATIONSHIP TO THE LOWER END OF SAID CUTOFF DIE, A STOP FOR ABUTMENT BY THE LOWER END OF THE BLANK DISPOSED ON THE AFORESAID VERTICAL LINE BELOW THE LEVEL OF THE FINGER, MEANS FOR RETAINING EACH BLANK AFTER IT IS CUT BUT RELEASING IT TO DROP BY GRAVITY AGAINST THE STOP IN TIMED RELATION TO THE REAWARD MOVEMENT OF THE CUT-OFF KNIFE, MEANS FOR OPERATING SAID WIRE FEEDING MEANS IN TIMED RELATION TO SAID SECOND DIE, AND MEANS FOR OPERATING SAID KNIFE IN TIMED RELATION TO SAID WIRE FEEDING MEANS, FINGER, AND SECOND DIE, WHEREBY A SINGLE BLANK OF THE PREDETERMINED LENGTH IS DROPPED BY GRAVITY ON THE AFORESAID VERTICAL LINE IN PROPER TIMED RELATIONSHIP TO FORWARD MOVEMENT OF THE FINGER AND SECOND DIE IN EACH CYCLE OF OPERATION OF THE MACHINE. 